OK, my attempt to use nested esxi VM's and the vmxnet3 vNIC for them connected to a 10GBe QLogic/HP NIC failed repeatedly in a PSOD.
I was just trying to get a fast datastore backbone from an iSCSI target on a set of SSD's.
So now my attention is going to the vmdk's and RDM. Is it possible to use an RDM in a nested esxi cluster from Workstation 9? I want to carve out a LUN from the host where Workstaion 9 is on and share that LUN / RDM to the 2 esxi VM's on this Workstation 9 machine. If so, can someone post a link to a "Dummy's" How to? 
I've tested a shared vmdk by adding the below entries to the .vmx file of the esxi VM's but I ran into a problem where one VM loses connection..
#Shared scsi1 data storage
scsi0:1.present = "TRUE"
scsi1.virtualDev = "lsilogic"
scsi1.sharedbus = "none"
scsi1:0.present = "FALSE"
scsi0:1.fileName = "D:\SharedVMDK\BlahBlah\yakyakyak.vmdk"
scsi0:1.mode = "independent-persistent"
scsi1:0.shared = "TRUE"
scsi1:0.redo = ""
scsi0:1.redo = ""
usb:0.present = "TRUE"
usb:0.deviceType = "hid"
usb:0.port = "0"
usb:0.parent = "-1"
Thanks